package com.zut.controller;

import com.zut.pojo.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;


/*
 *
 * 文件上传与下载
 *
 * */

@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;


     /*
     * 文件上传
     * */

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件就会被删除
        log.info(file.toString());
        //使用UUID重新生成文件名，防止文件名称重复导致覆盖
        String originalFilename = file.getOriginalFilename();
        String substring = originalFilename.substring(originalFilename.lastIndexOf("."));

        String fileName = UUID.randomUUID().toString() + substring;

        File dir = new File(basePath);
        //判断目录是否存在
        if (!dir.exists()){
            //不存在，创建目录
            dir.mkdir();

        }

        try {
            file.transferTo(new File(basePath + fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }

        return R.success(fileName);
    }


    /*
    * 文件下载
    * */

    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) throws IOException {
        //输入流，读取文件内容
        FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));
        //输出流，将文件内容写到浏览器
        ServletOutputStream outputStream = response.getOutputStream();

        response.setContentType("image/jpeg");

        int len = 0;
        byte[] bytes = new byte[1024];
        while ((len = fileInputStream.read(bytes)) != -1){

            outputStream.write(bytes,0,len);
            outputStream.flush();
        }

        fileInputStream.close();
        outputStream.close();
    }
}
